Plate Tectonics Vocabulary Lab

2. Drift The idea that continents have moved across Earth's surface over time.
6. The soft, flowing layer of the upper mantle beneath the lithosphere that allows tectonic plates to move.
7. Tectonics The theory that Earth's outer shell is divided into large plates that move over the mantle.
9. The rigid outer layer of Earth, made of the crust and the upper part of the mantle.
10. of Plate Tectonics The scientific theory explaining how and why Earth's plates move, and how that movement shapes Earth's surface.
12. Plate Boundaries Places where two plates move toward each other, causing collisions that can form mountains, volcanoes, or trenches.
13. A giant landmass made of all or most of Earth's continents joined together.

1. A supercontinent that existed about 200 million years ago and later broke apart into today's continents.
3. Plate Boundaries Places where two plates move apart, often forming new crust.
4. Ridge System An underwater mountain range formed at divergent boundaries in the ocean, where new crust is created.
5. Trenches Very deep valleys in the ocean floor formed at convergent boundaries where one plate sinks beneath another.
8. Plate A large piece of Earth's lithosphere that moves over the asthenosphere.
11. Plate Boundary A place where two plates slide past each other, often causing earthquakes.